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==================== Data Files Support ==================== Old packaging installation methods in the Python ecosystem have traditionally allowed installation of "data files", which are placed in a platform-specific location. However, the most common use case for data files distributed with a package is for use *by* the package, usually by including the data files **inside the package directory**. Setuptools focuses on this most common type of data files and offers three ways of specifying which files should be included in your packages, as described in the following sections. include_package_data ==================== First, you can simply use the ``include_package_data`` keyword. For example, if the package tree looks like this:: project_root_directory ├── setup.py # and/or setup.cfg, pyproject.toml └── src └── mypkg ├── __init__.py ├── data1.rst ├── data2.rst ├── data1.txt └── data2.txt and you supply this configuration: .. tab:: pyproject.toml .. code-block:: toml [tool.setuptools] # ... # By default, include-package-data is true in pyproject.toml, so you do # NOT have to specify this line. include-package-data = true [tool.setuptools.packages.find] where = ["src"] .. tab:: setup.cfg .. code-block:: ini [options] # ... packages = find: package_dir = = src include_package_data = True [options.packages.find] where = src .. tab:: setup.py .. code-block:: python from setuptools import setup, find_packages setup( # ..., packages=find_packages(where="src"), package_dir={"": "src"}, include_package_data=True ) then all the ``.txt`` and ``.rst`` files will be automatically installed with your package, provided: 1. These files are included via the :ref:`MANIFEST.in <Using MANIFEST.in>` file, like so:: include src/mypkg/*.txt include src/mypkg/*.rst 2. OR, they are being tracked by a revision control system such as Git, Mercurial or SVN, and you have configured an appropriate plugin such as :pypi:`setuptools-scm` or :pypi:`setuptools-svn`. (See the section below on :ref:`Adding Support for Revision Control Systems` for information on how to write such plugins.) .. note:: .. versionadded:: v61.0.0 The default value for ``tool.setuptools.include-package-data`` is ``True`` when projects are configured via ``pyproject.toml``. This behaviour differs from ``setup.cfg`` and ``setup.py`` (where ``include_package_data=False`` by default), which was not changed to ensure backwards compatibility with existing projects. package_data ============ By default, ``include_package_data`` considers **all** non ``.py`` files found inside the package directory (``src/mypkg`` in this case) as data files, and includes those that satisfy (at least) one of the above two conditions into the source distribution, and consequently in the installation of your package. If you want finer-grained control over what files are included, then you can also use the ``package_data`` keyword. For example, if the package tree looks like this:: project_root_directory ├── setup.py # and/or setup.cfg, pyproject.toml └── src └── mypkg ├── __init__.py ├── data1.rst ├── data2.rst ├── data1.txt └── data2.txt then you can use the following configuration to capture the ``.txt`` and ``.rst`` files as data files: .. tab:: pyproject.toml .. code-block:: toml [tool.setuptools.packages.find] where = ["src"] [tool.setuptools.package-data] mypkg = ["*.txt", "*.rst"] .. tab:: setup.cfg .. code-block:: ini [options] # ... packages = find: package_dir = = src [options.packages.find] where = src [options.package_data] mypkg = *.txt *.rst .. tab:: setup.py .. code-block:: python from setuptools import setup, find_packages setup( # ..., packages=find_packages(where="src"), package_dir={"": "src"}, package_data={"mypkg": ["*.txt", "*.rst"]} ) The ``package_data`` argument is a dictionary that maps from package names to lists of glob patterns. Note that the data files specified using the ``package_data`` option neither require to be included within a :ref:`MANIFEST.in <Using MANIFEST.in>` file, nor require to be added by a revision control system plugin. .. note:: If your glob patterns use paths, you *must* use a forward slash (``/``) as the path separator, even if you are on Windows. Setuptools automatically converts slashes to appropriate platform-specific separators at build time. .. important:: Glob patterns do not automatically match dotfiles, i.e., directory or file names starting with a dot (``.``). To include such files, you must explicitly start the pattern with a dot, e.g. ``.*`` to match ``.gitignore``. If you have multiple top-level packages and a common pattern of data files for all these packages, for example:: project_root_directory ├── setup.py # and/or setup.cfg, pyproject.toml └── src ├── mypkg1 │ ├── data1.rst │ ├── data1.txt │ └── __init__.py └── mypkg2 ├── data2.txt └── __init__.py Here, both packages ``mypkg1`` and ``mypkg2`` share a common pattern of having ``.txt`` data files. However, only ``mypkg1`` has ``.rst`` data files. In such a case, if you want to use the ``package_data`` option, the following configuration will work: .. tab:: pyproject.toml .. code-block:: toml [tool.setuptools.packages.find] where = ["src"] [tool.setuptools.package-data] "*" = ["*.txt"] mypkg1 = ["data1.rst"] .. tab:: setup.cfg .. code-block:: ini [options] packages = find: package_dir = = src [options.packages.find] where = src [options.package_data] * = *.txt mypkg1 = data1.rst .. tab:: setup.py .. code-block:: python from setuptools import setup, find_packages setup( # ..., packages=find_packages(where="src"), package_dir={"": "src"}, package_data={"": ["*.txt"], "mypkg1": ["data1.rst"]}, ) Notice that if you list patterns in ``package_data`` under the empty string ``""`` in ``setup.py``, and the asterisk ``*`` in ``setup.cfg`` and ``pyproject.toml``, these patterns are used to find files in every package. For example, we use ``""`` or ``*`` to indicate that the ``.txt`` files from all packages should be captured as data files. These placeholders are treated as a special case, ``setuptools`` **do not** support glob patterns on package names for this configuration (patterns are only supported on the file paths). Also note how we can continue to specify patterns for individual packages, i.e. we specify that ``data1.rst`` from ``mypkg1`` alone should be captured as well. .. note:: When building an ``sdist``, the data files are also drawn from the ``package_name.egg-info/SOURCES.txt`` file which works as a form of cache. So make sure that this file is removed if ``package_data`` is updated, before re-building the package. .. attention:: In Python any directory is considered a package (even if it does not contain ``__init__.py``, see *native namespaces packages* on :doc:`PyPUG:guides/packaging-namespace-packages`). Therefore, if you are not relying on :doc:`automatic discovery </userguide/package_discovery>`, you *SHOULD* ensure that **all** packages (including the ones that don't contain any Python files) are included in the ``packages`` configuration (see :doc:`/userguide/package_discovery` for more information). Moreover, it is advisable to use full packages name using the dot notation instead of a nested path, to avoid error prone configurations. Please check :ref:`section subdirectories <subdir-data-files>` below. exclude_package_data ==================== Sometimes, the ``include_package_data`` or ``package_data`` options alone aren't sufficient to precisely define what files you want included. For example, consider a scenario where you have ``include_package_data=True``, and you are using a revision control system with an appropriate plugin. Sometimes developers add directory-specific marker files (such as ``.gitignore``, ``.gitkeep``, ``.gitattributes``, or ``.hgignore``), these files are probably being tracked by the revision control system, and therefore by default they will be included when the package is installed. Supposing you want to prevent these files from being included in the installation (they are not relevant to Python or the package), then you could use the ``exclude_package_data`` option: .. tab:: pyproject.toml .. code-block:: toml [tool.setuptools.packages.find] where = ["src"] [tool.setuptools.exclude-package-data] mypkg = [".gitattributes"] .. tab:: setup.cfg .. code-block:: ini [options] # ... packages = find: package_dir = = src include_package_data = True [options.packages.find] where = src [options.exclude_package_data] mypkg = .gitattributes .. tab:: setup.py .. code-block:: python from setuptools import setup, find_packages setup( # ..., packages=find_packages(where="src"), package_dir={"": "src"}, include_package_data=True, exclude_package_data={"mypkg": [".gitattributes"]}, ) The ``exclude_package_data`` option is a dictionary mapping package names to lists of wildcard patterns, just like the ``package_data`` option. And, just as with that option, you can use the empty string key ``""`` in ``setup.py`` and the asterisk ``*`` in ``setup.cfg`` and ``pyproject.toml`` to match all top-level packages. Any files that match these patterns will be *excluded* from installation, even if they were listed in ``package_data`` or were included as a result of using ``include_package_data``. .. _subdir-data-files: Subdirectory for Data Files =========================== A common pattern is where some (or all) of the data files are placed under a separate subdirectory. For example:: project_root_directory ├── setup.py # and/or setup.cfg, pyproject.toml └── src └── mypkg ├── data │ ├── data1.rst │ └── data2.rst ├── __init__.py ├── data1.txt └── data2.txt Here, the ``.rst`` files are placed under a ``data`` subdirectory inside ``mypkg``, while the ``.txt`` files are directly under ``mypkg``. In this case, the recommended approach is to treat ``data`` as a namespace package (refer :pep:`420`). With ``package_data``, the configuration might look like this: .. tab:: pyproject.toml .. code-block:: toml # Scanning for namespace packages in the ``src`` directory is true by # default in pyproject.toml, so you do NOT need to include the # `tool.setuptools.packages.find` if it looks like the following: # [tool.setuptools.packages.find] # namespaces = true # where = ["src"] [tool.setuptools.package-data] mypkg = ["*.txt"] "mypkg.data" = ["*.rst"] .. tab:: setup.cfg .. code-block:: ini [options] # ... packages = find_namespace: package_dir = = src [options.packages.find] where = src [options.package_data] mypkg = *.txt mypkg.data = *.rst .. tab:: setup.py .. code-block:: python from setuptools import setup, find_namespace_packages setup( # ..., packages=find_namespace_packages(where="src"), package_dir={"": "src"}, package_data={ "mypkg": ["*.txt"], "mypkg.data": ["*.rst"], } ) In other words, we allow Setuptools to scan for namespace packages in the ``src`` directory, which enables the ``data`` directory to be identified, and then, we separately specify data files for the root package ``mypkg``, and the namespace package ``data`` under the package ``mypkg``. With ``include_package_data`` the configuration is simpler: you simply need to enable scanning of namespace packages in the ``src`` directory and the rest is handled by Setuptools. .. tab:: pyproject.toml .. code-block:: toml [tool.setuptools] # ... # By default, include-package-data is true in pyproject.toml, so you do # NOT have to specify this line. include-package-data = true [tool.setuptools.packages.find] # scanning for namespace packages is true by default in pyproject.toml, so # you need NOT include the following line. namespaces = true where = ["src"] .. tab:: setup.cfg .. code-block:: ini [options] packages = find_namespace: package_dir = = src include_package_data = True [options.packages.find] where = src .. tab:: setup.py .. code-block:: python from setuptools import setup, find_namespace_packages setup( # ... , packages=find_namespace_packages(where="src"), package_dir={"": "src"}, include_package_data=True, ) Summary ======= In summary, the three options allow you to: ``include_package_data`` Accept all data files and directories matched by :ref:`MANIFEST.in <Using MANIFEST.in>` or added by a :ref:`plugin <Adding Support for Revision Control Systems>`. ``package_data`` Specify additional patterns to match files that may or may not be matched by :ref:`MANIFEST.in <Using MANIFEST.in>` or added by a :ref:`plugin <Adding Support for Revision Control Systems>`. ``exclude_package_data`` Specify patterns for data files and directories that should *not* be included when a package is installed, even if they would otherwise have been included due to the use of the preceding options. .. note:: Due to the way the build process works, a data file that you include in your project and then stop including may be "orphaned" in your project's build directories, requiring you to manually deleting them. This may also be important for your users and contributors if they track intermediate revisions of your project using Subversion; be sure to let them know when you make changes that remove files from inclusion so they can also manually delete them. .. _Accessing Data Files at Runtime: Accessing Data Files at Runtime =============================== Typically, existing programs manipulate a package's ``__file__`` attribute in order to find the location of data files. For example, if you have a structure like this:: project_root_directory ├── setup.py # and/or setup.cfg, pyproject.toml └── src └── mypkg ├── data │ └── data1.txt ├── __init__.py └── foo.py Then, in ``mypkg/foo.py``, you may try something like this in order to access ``mypkg/data/data1.txt``: .. code-block:: python import os data_path = os.path.join(os.path.dirname(__file__), 'data', 'data1.txt') with open(data_path, 'r') as data_file: ... However, this manipulation isn't compatible with :pep:`302`-based import hooks, including importing from zip files and Python Eggs. It is strongly recommended that, if you are using data files, you should use :mod:`importlib.resources` to access them. In this case, you would do something like this: .. code-block:: python from importlib.resources import files data_text = files('mypkg.data').joinpath('data1.txt').read_text() :mod:`importlib.resources` was added to Python 3.7. However, the API illustrated in this code (using ``files()``) was added only in Python 3.9, [#files_api]_ and support for accessing data files via namespace packages was added only in Python 3.10 [#namespace_support]_ (the ``data`` subdirectory is a namespace package under the root package ``mypkg``). Therefore, you may find this code to work only in Python 3.10 (and above). For other versions of Python, you are recommended to use the :pypi:`importlib-resources` backport which provides the latest version of this library. In this case, the only change that has to be made to the above code is to replace ``importlib.resources`` with ``importlib_resources``, i.e. .. code-block:: python from importlib_resources import files ... See :doc:`importlib-resources:using` for detailed instructions. .. tip:: Files inside the package directory should be *read-only* to avoid a series of common problems (e.g. when multiple users share a common Python installation, when the package is loaded from a zip file, or when multiple instances of a Python application run in parallel). If your Python package needs to write to a file for shared data or configuration, you can use standard platform/OS-specific system directories, such as ``~/.local/config/$appname`` or ``/usr/share/$appname/$version`` (Linux specific) [#system-dirs]_. A common approach is to add a read-only template file to the package directory that is then copied to the correct system directory if no pre-existing file is found. Data Files from Plugins and Extensions ====================================== You can resort to a :doc:`native/implicit namespace package <PyPUG:guides/packaging-namespace-packages>` (as a container for files) if you want plugins and extensions to your package to contribute with package data files. This way, all files will be listed during runtime when :doc:`using importlib.resources <importlib-resources:using>`. Note that, although not strictly guaranteed, mainstream Python package managers, like :pypi:`pip` and derived tools, will install files belong to multiple distributions that share a same namespace into the same directory in the file system. This means that the overhead for :mod:`importlib.resources` will be minimum. Non-Package Data Files ====================== Historically, ``setuptools`` by way of ``easy_install`` would encapsulate data files from the distribution into the egg (see `the old docs <https://github.com/pypa/setuptools/blob/52aacd5b276fedd6849c3a648a0014f5da563e93/docs/setuptools.txt#L970-L1001>`_). As eggs are deprecated and pip-based installs fall back to the platform-specific location for installing data files, there is no supported facility to reliably retrieve these resources. Instead, the PyPA recommends that any data files you wish to be accessible at run time be included **inside the package**. ---- .. [#system-dirs] These locations can be discovered with the help of third-party libraries such as :pypi:`platformdirs`. .. [#files_api] Reference: https://importlib-resources.readthedocs.io/en/latest/using.html#migrating-from-legacy .. [#namespace_support] Reference: https://github.com/python/importlib_resources/pull/196#issuecomment-734520374
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